A 39-year-old man was stabbed during a figh on a SETPA bus in West Philadelphia early Monday morning, authorities said.
The incident began around 2:44 a.m. when two men got on the L1 Owl bus at 15th and Market streets and began fighting, police said.
The bus driver flagged down a nearby Philadelphia police officer for assistance.
After an unsuccessful attempt to separate the men, the officer deployed a Taser on the 39-year-old man, whom police did not identify.
While taking him into custody, the officer saw that the man had been stabbed. He was taken to Jefferson Hospital, where he remained in stable condition late Monday morning.
Investigators are looking for a the second person who they said was involved in the fight and fled the scene.
Officers recovered a knife. Police gave no motive for the crime, which remains under investigation.